Histological and immunophenotypic profile of nasal NK/T cell lymphomas from Peru: high prevalence of p53 overexpression

Single-Cell Analysis Reveals Malignant Cells Reshape the Cellular Landscape and Foster an Immunosuppressive Microenvironment of Extranodal NK/T-Cell Lymphoma

Extranodal natural killer/T-cell lymphoma (NKTCL) is an aggressive type of lymphoma associated with Epstein-Barr virus (EBV) and characterized by heterogeneous tumor behaviors. To better understand the origins of the heterogeneity, this study utilizes single-cell RNA sequencing (scRNA-seq) analysis to profile the tumor microenvironment (TME) of NKTCL at the single-cell level. Together with in vitro and in vivo models, the study identifies a subset of LMP1+ malignant NK cells contributing to the tumorigenesis and development of heterogeneous malignant cells in NKTCL. Furthermore, malignant NK cells interact with various immunocytes via chemokines and their receptors, secrete substantial DPP4 that impairs the chemotaxis of immunocytes and regulates their infiltration. They also exhibit an immunosuppressive effect on T cells, which is further boosted by LMP1. Moreover, high transcription of EBV-encoded genes and low infiltration of tumor-associated macrophages (TAMs) are favorable prognostic indicators for NKTCL in multiple patient cohorts. This study for the first time deciphers the heterogeneous composition of NKTCL TME at single-cell resolution, highlighting the crucial role of malignant NK cells with EBV-encoded LMP1 in reshaping the cellular landscape and fostering an immunosuppressive microenvironment. These findings provide insights into understanding the pathogenic mechanisms of NKTCL and developing novel therapeutic strategies against NKTCL.

Disseminated Nasal subtype Extranodal NK/T-cell lymphoma and its diagnostic difficulties in antemortem biopsies

Extranodal NK/T- cell lymphoma (ENKTCL) is an aggressive lymphoma driven by Epstein-Barr virus (EBV) infection in genetically susceptible individuals. It was historically called a lethal midline granuloma. Due to the angio-destructive nature of ENKTCL, lymphoma cells are often accompanied and masked by necrosis and dense inflammation in the biopsy. Further, the biopsy may show vasculitis, which can mimic granulomatosis with polyangiitis. Due to these masquerades, ENKTCL is often misdiagnosed in the biopsy. Several biopsies may be required to establish the diagnosis. We describe the clinical course and autopsy findings of a young female who presented with a hard-palate ulcer. Antemortem biopsies failed to establish the diagnosis. The autopsy revealed an advanced nasal subtype of Extranodal NK/T-cell lymphoma with dissemination to the kidneys, adrenals, liver, spleen, and small intestine.

Extranodal Natural Killer/T-Cell Lymphomas: Current Approaches and Future Directions

Extranodal natural killer/T(NK/T)-cell lymphoma (ENKTL) is a rare subtype of non-Hodgkin lymphoma that typically presents with an isolated nasal mass, but a sizeable minority present with advanced stage disease and have a significantly poorer prognosis. Those with limited disease are standardly treated with chemotherapy and radiation while those with advanced stage disease are treated with L-asparaginase containing chemotherapy regimens. The addition of modern radiation therapy techniques and the incorporation of L-asparaginase into chemotherapy regimens have significantly improved outcomes in this disease, but relapses and death from relapsed disease remain frequent. Given the high rate of relapse, several novel therapies have been evaluated for the treatment of this disease. In this review, we explore the current standard of care for ENKTL as well as novel therapies that have been evaluated for its treatment and the biologic understanding behind these therapies.

What Effect Does Epstein-Barr Virus Have on Extranodal Natural Killer/T-Cell Lymphoma Prognosis? A Review of 153 Reported Cases

The primary aim of this review is to identify the relationship between Epstein-Barr virus (EBV) and prognosis in extranodal natural killer/T-cell lymphoma (ENKTL). Additionally, a literature review of ENKTL was carried out. The investigators designed and implemented a 21-year literature review using the online databases PubMed and Google Scholar. The total number of cases analyzed was 153 (64 case reports; one comparative study; one systematic review). Information related to ENKTL from July 1999 to February 2021 was included in the study. Study variables included: patient demographics, tumor classification, screening modalities, tumor characteristics, symptomatology, treatment, and prognosis. The average age at diagnosis was 50.9 years (range: 4-90 years). Patients of Asian ethnicity were most commonly affected, and there was a 1.6:1 male to female ratio. ENKTL was most frequently detected in the head and neck region, and 53.1% of cases metastasized. Of all head and neck cases, the nose was the most affected location. Immunohistochemistry positivity included: EBV (32.0%), CD2 (96.6%), CD3ϵ (81.7%), CD43 (91.7%), CD56 (86.4%), Granzyme (97.1%), Perforin (90.9%), TIA-1 (97.8%), p53 (33.3%). The most frequently employed single treatment modality was chemotherapy alone, and 34.2% of patients expired within five years of diagnosis. The average follow-up period was 16.51 months (range: 0.25-66 months). EBV was significantly associated with metastatic ENKTL (χ² = 4.36; CV = 3.84; p = 0.037). We found no association between EBV and ENKTL prognosis (χ² = 17.2; CV = 21.0; p = 0.14).

NK-/T-cell lymphomas

Natural killer/T-cell lymphoma (NKTL) is a sub-type of Epstein-Barr virus (EBV)-related non-Hodgkin lymphomas common in Asia and Latin America but rare elsewhere. Its pathogenesis is complex and incompletely understood. Lymphoma cells are transformed from NK- or T-cells, sometimes both. EBV-infection and subsequent genetic alterations in infected cells are central to NKTL development. Hemophagocytic syndrome is a common complication. Accurate staging is important to predict outcomes but there is controversy which system is best. More than two-thirds of NKTL lympohmas are localized at diagnosis, are frequently treated with radiation therapy only and have 5-year survival of about 70 percent. Persons with advanced NKTLs receive radiation therapy synchronously or metachronously with diverse multi-drug chemotherapy typically including L-asparginase with 5-year survival of about 40 percent. Some persons with widespread NKTL receive chemotherapy only. There are few data on safety and efficacy of high-dose therapy and a haematopoietic cell autotransplant. Immune therapies, histone deacetylase (HDAC)-inhibitors and other drugs are in early clinical trials. There are few randomized controlled clinical trials in NKTLs and no therapy strategy is clearly best; more effective therapy(ies) are needed. Some consensus recommendations are not convincingly evidence-based. Mechanisms of multi-drug resistance are considered. We discuss these issues including recent advances in our understanding of and therapy of NKTLs.

EBV and the Pathogenesis of NK/T Cell Lymphoma

Epstein-Barr virus (EBV) is a ubiquitous gamma herpes virus with tropism for B cells. EBV is linked to the pathogenesis of B cell, T cell and NK cell lymphoproliferations, with extranodal NK/T cell lymphoma, nasal type (ENKTCL) being the prototype of an EBV-driven lymphoma. ENKTCL is an aggressive neoplasm, particularly widespread in East Asia and the native population of Latin America, which suggests a strong genetic predisposition. The link between ENKTCL and different populations has been partially explored. EBV genome sequencing analysis recognized two types of strains and identified variants of the latent membrane protein 1 (LMP1), which revealed different oncogenic potential. In general, most ENKTCL patients carry EBV type A with LMP1 wild type, although the LMP1 variant with a 30 base pair deletion is also common, especially in the EBV type B, where it is necessary for oncogenic transformation. Contemporary high-throughput mutational analyses have discovered recurrent gene mutations leading to activation of the JAK-STAT pathway, and mutations in other genes such as BCOR, DDX3X and TP53. The genomic landscape in ENKTCL highlights mechanisms of lymphomagenesis, such as immune response evasion, secondary to alterations in signaling pathways or epigenetics that directly or indirectly interfere with oncogenes or tumor suppressor genes. This overview discusses the most important findings of EBV pathogenesis and genetics in ENKTCL.

Algorithmic Approach to Fibroinflammatory Sinonasal Tract Lesions

Fibroinflammatory lesions of the sinonasal tract are one of the most common head and neck lesions submitted to surgical pathology. When the fibroinflammatory pattern represents the lesion (i.e., not surface reactive ulceration), an algorithmic approach can be useful. Separated into reactive, infectious, and neoplastic, and then further divided based on common to rare, this logical progression through a series of differential considerations allows for many of these lesions to be correctly diagnosed. The reactive lesions include chronic rhinosinusitis and polyps, granulomatosis with polyangiitis, and eosinophilic angiocentric fibrosis. Infectious etiologies include acute invasive fungal rhinosinusitis, rhinoscleroma, and mycobacterial infections. The neoplastic category includes lobular capillary hemangioma, inflammatory myofibroblastic tumor, and NK/T-cell lymphoma, nasal type. Utilizing patterns of growth, dominant cell types, and additional histologic features, selected ancillary studies help to confirm the diagnosis, guiding further clinical management.

High-grade B-Cell Lymphoma With MYC, BCL2, and/or BCL6 Translocations/Rearrangements: Clinicopathologic Features of 51 Cases in a Single Institution of South China

Double-hit/triple-hit lymphomas (DH/THLs) are high-grade B-cell lymphomas with MYC and BCL2 rearrangements and/or BCL6 rearrangements, which have poor outcomes after standard chemoimmunotherapy. This retrospective study analyzed 51 patients (range, 19 to 82 y) diagnosed from 2016 to 2019 and treated for DH/THL (n=34 MYC/BCL6 DHL, n=14 MYC/BCL2 DHL, n=3 THL) at one institution in South China. Extranodal lesions occurred in 32 patients (62.7%), more frequently in MYC/BCL6 DHL (22/34, 64.7%) than in MYC/BCL2 DHL (7/14, 50%). The most common extranodal sites were the stomach (8/32, 25.0%) and intestine (5/32, 15.6%). Most patients (33/45, 73.3%) presented with Ann Arbor stage III/IV. Interestingly, 14.3% (4/28) of MYC/BCL6 DHL tumors showed diffuse, medium-intensity CD30 expression. Epstein-Barr virus-encoded RNA was positive in 3 cases, all MYC/BCL6 DHL. Among 48 patients (94.1%) with follow-up data, 18 (37.5%) died owing to the disease, and the median survival was 5.5 months. Germinal center B cells were observed more frequently in MYC/BCL2 DHL (14/14, 100.0%) than in MYC/BCL6 DHL (15/34, 44.1%; P<0.001). Bone marrow involvement tended to lower overall survival (OS) (P=0.033). No association was observed between stage, B symptoms, lactate dehydrogenase levels, and central nervous system involvement and OS. A total of 25 patients (25/47, 53.2%) with previous hepatitis B virus (HBV) infections had significantly poorer OS (P=0.014). Chronic HBV infection was positively correlated with MYC/BCL6 DHL (r=0.317, P=0.030). Compared with DH/THL in western countries, the disease in South China has distinct characteristics with a higher prevalence of MYC/BCL6 DHL. We speculate that HBV is important in DH/THL tumorigenesis. These findings might provide clues for novel treatment strategies.

Lymphotropic Viruses EBV, KSHV and HTLV in Latin America: Epidemiology and Associated Malignancies. A Literature-Based Study by the RIAL-CYTED

The Epstein-Barr virus (EBV), Kaposi sarcoma herpesvirus (KSHV) and human T-lymphotropic virus (HTLV-1) are lymphomagenic viruses with region-specific induced morbidity. The RIAL-CYTED aims to increase the knowledge of lymphoma in Latin America (LA), and, as such, we systematically analyzed the literature to better understand our risk for virus-induced lymphoma. We observed that high endemicity regions for certain lymphomas, e.g., Mexico and Peru, have a high incidence of EBV-positive lymphomas of T/NK cell origin. Peru also carries the highest frequency of EBV-positive classical Hodgkin lymphoma (HL) and EBV-positive diffuse large B cell lymphoma, not otherwise specified (NOS), than any other LA country. Adult T cell lymphoma is endemic to the North of Brazil and Chile. While only few cases of KSHV-positive lymphomas were found, in spite of the close correlation of Kaposi sarcoma and the prevalence of pathogenic types of KSHV. Both EBV-associated HL and Burkitt lymphoma mainly affect young children, unlike in developed countries, in which adolescents and young adults are the most affected, correlating with an early EBV seroconversion for LA population despite of lack of infectious mononucleosis symptoms. High endemicity of KSHV and HTLV infection was observed among Amerindian populations, with differences between Amazonian and Andean populations.

[Peripheral T cell lymphomas: diagnosis and treatment]

Peripheral T cell lymphomas are rare malignancies with aggressive course, with several different subtype described in the 2016 WHO classification. Their distribution across the world is heterogenous, with marked difference between Western and Asian country. Their clinical presentation often comprise extra-nodal involvement, B symptoms and immune system disorder which can lead to wrong diagnosis orientation. Make a right diagnosis need a experienced pathologist in close collaboration with clinical datas. Peripheral T cell lymphomas are in general associated with poor prognosis when treated with anthracyclines-based regimen, and several studies and trials focused on the use of intensified regimen or novel targeted agents, whose proper indication still remain to be clarified.

Extranodal NK/T-cell lymphoma, nasal type without evidence of EBV infection

Extranodal natural killer/T cell lymphoma-nasal type (EN-NK/T-NT) is extremely rare in Western countries; however, it is the most common subtype of peripheral T cell lymphoma in China. Despite this, there are a limited number of clinicopathological research studies on Epstein-Barr virus (EBV)-negative EN-NK/T-NTs. EBV-negative EN-NK/T-NT is a rare disease type, which has not been fully investigated. If other diagnostic criteria are met, such as the lesions being located predominantly in the upper aerodigestive tract, the presence of angiocentricity or angioinvasion, necrosis and expression of NK/T-cell phenotype, EN-NK/T-NT may be diagnosed, even if EBV is negative. In the present study, 99 cases of EN-NK/T-NTs were analyzed retrospectively, among which seven cases were EBV-negative EN-NK/T-NTs and selected for further investigation. In addition, the present study reviewed previously published research into EN-NK/T-NT, highlighting that EBV-negative EN-NK/T-NT is rare and that its geographical distribution is mainly in countries in Asia, Central America and South America. Patients with EBV-negative EN-NK/T-NT were all of Chinese ethnicity, with a median age of 32 years and primarily female. Furthermore, these patients shared similar clinicopathological characteristics (such as the tumor occurring mainly in the upper aerodigestive tract, the presence of vascular destruction, necrosis and cytotoxic phenotypes) to patients with EBV-positive EN-NK/T-NT. Immunohistochemistry and molecular analysis results indicated that tumor cells were primarily of NK or cytotoxic T origin; however, EBV-encoded small RNAs were not detected in any of these cases. Among the immunochemistry markers, T-bet was statistical significantly different between EBV-positive and -negative cases. Fluorescence in situ hybridization was also performed in two EBV-negative cases, including one case with a co-deletion of 6q21 and PR/SET domain 1 genes. There was only available follow-up data in 3/5 patients who survived for 37–113 months (median, 40 months). As EN-NK/T-NT can be diagnosed, even when EBV is negative, awareness of this subtype may prevent misdiagnosis or delayed diagnosis.

Primary extranodal natural killer/T-cell nasal-type lymphoma of spine: A case report

RATIONALE

Primary Extranodal Natural Killer/T-Cell Nasal-Type Lymphoma (ENKTCL) of spine is rarely reported. This case study presents a rare case of ENKTCL originating from the sixth thoracic vertebra.

PATIENT CONCERNS

Here, we present a case of 49-year-old Asian male with chest and back pain. Physical examination revealed the myodynamia of both lower limbs decreased from IV degree to 0 degree, reflexes of both lower limbs and a large area of cutaneous sensation below xiphoid process disappeared in 3 days.

DIAGNOSES

In immunophenotype analysis, CD2, CD3, CD7, and CD68 were positive and CD56 was suspiciously positive. Granzyme B and T-cell intracellular antigen (TIA-1) were also positive and in situ hybridization was positive for Epstein-Barr virus-encoded mRNA (EBER). Ki-67 was 60%+. Nuclide bone scan showed that the nuclide was unusually concentrated in the sixth thoracic vertebra which considered extremely active and slightly concentrated in the right sacrolilac joint. Magnetic resonance imaging detected an abnormal signal in the sixth thoracic vertebra with corresponding paravertebral and intraspinal occupying lesion. Based on the above features, a diagnosis of ENKTCL was made.

INTERVENTIONS

This patient was treated with surgery and symptomatic supportive treatment.

OUTCOMES

The myodynamia of patient's both lower limbs were elevated to I degree after the operation with chest and back pain partly relieved. However, the patient died about 3 months later.

LESSONS

ENKTCL could originate from spine. Clinicians should be alert for early stage diagnose and distinguish it from some common spinal tumor such as neurofibroma and hemangioma.

Extranodal NK/T-Cell Lymphoma, Nasal Type in Guatemala: An 86-Case Series Emphasizing Clinical Presentation and Microscopic Characteristics

Extranodal NK/T-cell lymphoma, nasal type (ENKTCL-NT) is a lymphoid malignancy that mainly affects the nasopharynx and is associated with the Epstein-Barr virus (EBV). Increased incidence is seen in some Latin American and Asian countries. In this study, we describe a case series of 86 Guatemalan patients with ENKTCL-NT from a single diagnostic head and neck center. We emphasize the distinctive clinical, microscopic, and immunohistochemical (IHC) features, as well as EBV positivity by in situ hybridization (ISH). Most of the patients (90.6%) were of Mayan descent and low socioeconomic status (SES). Males were more often affected than females, comprising 68.3% of cases. Patient age ranged from 8 to 71, with a mean of 34.7 years. All cases arose in the upper aerodigestive tract and mainly presented as a rapidly progressive, necrotizing midfacial process affecting the nasal, nasopharyngeal, sinonasal, palatal, and oropharyngeal structures. Microscopically, ENKTCL-NT showed a diffuse polymorphic and atypical lymphoid infiltrate. Angiocentric and angiodestructive growth patterns were present with associated necrosis. Peripheral hyaline necrosis of blood vessels was a histologic hallmark. The ISH and IHC profiles included positivity of EBV, LCA, CD3, CD45RO, CD30 (focal in 39.2%), granzyme-B, TIA-1, perforin (in 82.3%), and CD56 (in 83.7%). CD20 was negative, and the Ki-67 index ranged from 70 to 90%. In Guatemala, this lymphoma is strongly associated with people of low SES and indigenous ethnicity. When affected, the palatal mucosa provides the best site to obtain a representative biopsy. Since ENKTCL-NT is highly aggressive, it is extremely important to recognize the spectrum of clinical presentations and microscopic features in order to avoid misdiagnosis and treatment delay.

Extranodal NK/T-cell lymphoma in adolescents: imaging findings of a consecutive 7-year case series

Objectives

Extranodal NK/T-cell lymphoma is reportedly a rare but emerging type of lymphoma in adolescents. The present study was performed to specify its imaging characteristics.

Methods

Our hospital’s picture archiving and communication systems were searched from January 2009 to December 2016. We identified 13 patients aged <18 years with pathologically confirmed extranodal NK/T-cell lymphoma in the head and neck region. The computed tomography and magnetic resonance images were reviewed to summarize the imaging characteristics of extranodal NK/T-cell lymphoma in adolescents.

Results

The mean age at onset was 15.2 ± 1.46 years (range, 12–17 years) with a male:female ratio of 1.17:1.00. Most of the patients (n = 10) displayed nasal cavity and/or paranasal involvement. The tumor was homogeneous in both computed tomography and magnetic resonance images and showed slight enhancement. No calcification or liquefactive necrosis was observed. Adjacent structures were usually involved.

Conclusion

Suggestive imaging characteristics could acquaint specialists with extranodal NK/T-cell lymphoma in adolescents, facilitating improved early recognition of the diagnosis and helping to improve the patient’s outcome.

Epstein-Barr Virus-Associated T and NK-Cell Lymphoproliferative Diseases

EBV-associated T and NK-cell lymphoproliferative diseases (EBV-T/NK LPDs) are characterized by the transformation and proliferation of EBV-infected T or NK cells. The 2016 revised World Health Organization classification recognizes the following EBV-positive lymphoproliferative disorders (LPD): chronic active EBV infection (CAEBV) of T- and NK-cell type (cutaneous and systemic forms), systemic EBV-positive T-cell lymphoma of childhood, aggressive NK-cell leukemia, extranodal NK/T-cell lymphoma, nasal type, and the new provisional entity primary EBV-positive nodal T/NK-cell lymphoma. EBV-associated hemophagocytic lymphohistiocytosis (HLH), although not included in the WHO classification because it is a reactive, inflammatory disease, is included in this review because it can be life-threatening and may have overlapping features with other EBV+ T/NK LPDs. EBV+ T/NK LPDs are rare diseases difficult to diagnose and manage properly, because some LPDs have unusual presentations, and discrepancies between clinical and histological findings might be encountered. Furthermore, EBV+ T/NK disorders share some clinico-pathological features, and may evolve into other categories during the clinical course, including malignant transformation of CAEBV. Here, we review the EBV+ T/NK LPDs in terms of their definitions, clinical features, histology, immunophenotype, molecular findings, and pathogenesis. This review aims to increase our understanding and awareness of the differential diagnosis among the different EBV+ T/NK LPDs. New insights into the genetic characteristics of these disorders will also be discussed.

Epidemiology and Pathology of T- and NK-Cell Lymphomas

PURPOSE

This review will describe and update readers on the recent changes in the 2017 WHO classification regarding peripheral T-cell lymphomas.

RECENT FINDINGS

Signficant advances in molecular studies have resulted in revisions to the classification as well as introduction to provisional entities such as breast implant-associated ALCL and nodal PTCL with T-follicular helper phenotype.

SUMMARY

Major advances in molecular and gene expression profiling has expanded our knowledge of these rare and aggressive diseases.

Rare case of low-grade extranodal NK/T-cell lymphoma, nasal type, arising in the setting of chronic rhinosinusitis and harboring a novel N-terminal KIT mutation

Background

Extranodal NK/T-cell lymphoma, nasal type (ENKTCL-NT), is a rare aggressive subtype of non-Hodgkin lymphoma characterized by angioinvasion, angiodestruction, necrosis and strong association with Epstein-Barr virus (EBV). ENKTCL-NT occurs worldwide and is more prevalent in Asian and the Native American populations of Mexico, Central and South America. It represents approximately 10% of all peripheral T-cell lymphomas worldwide. The aim of this report is to present a rare case of ENKTCL-NT with an unusually indolent clinical course and low-grade histopathologic features.

Case presentation

A 71-year-old Asian woman with a long-standing history of seasonal rhinosinusitis presented with persistent nasal congestion, cough, and fever unresponsive to antihistamines and antibiotics. Histopathological evaluation of a polypoid nasal mass revealed an atypical infiltrate with predominantly small lymphoid cells that were CD2+, surface CD3-, cytoplasmic CD3+, CD5(dim)+, CD7(dim)+, cytotoxic markers (granzyme B and perforin)+, EBER+ and CD56-. The Ki-67 proliferative index was very low (< 1%). T-cell receptor gamma gene rearrangement studies were positive for a monoclonal rearrangement, and sequencing studies identified a novel KIT mutation (p. K167 M, c. 500 A > T). A diagnosis of low-grade ENKTCL-NT was rendered.

Conclusions

Our case of ENKTCL-NT is unusual due to (1) an indolent clinical course (2) low-grade histopathologic features including a low proliferative index (3) lack of CD56 expression and (4) a novel KIT mutation. This case raises awareness of the existence of a subset of cases of ENKTCL-NT that can potentially be misdiagnosed as a reactive process, particularly in patients with recurrent chronic rhinosinusitis.

Specific Soft-Tissue Invasion and LMP1 Expression Are Potential Indicators of Extranodal NK/T Cell Lymphoma, Nasal Type

BACKGROUND Extranodal NK/T cell lymphoma, nasal type (ENKTL-NT) is difficult to distinguish from nasal polyps and inverted papilloma, leading to its high misdiagnosis ratio. The aim of this study was to investigate its potential prognostic indicators. MATERIAL AND METHODS Kaplan-Meier method was used to calculate overall survival (OS) rate. Cox proportional hazards regression was used to analyze risk ratios (ORs) with 95% confidence intervals (CIs). RESULTS Nasal ala infiltration and nasal floor thickness >2.0 mm or nasal septum thickness >2.5 mm were potential prognostic factors for OS (p=0.0323 and 0.0072, respectively). Cox proportional-hazards regression indicated that high LMP1 expression and the nasal floor thickness >2.0 mm or nasal septum thickness >2.5 mm were the independent risk factors for poor OS of ENKTL-NT (HR=3.0655, p=0.028; HR=2.3650, p=0.0452, respectively). In the subgroup analysis, the OS rate was lower when the nasal floor thickness >2.0 mm or nasal septum thickness >2.5 mm in the patients who had high expression of LMP1 (p=0.0651), whereas high LMP1 expression increased the risk of worse prognostic outcome in patients with deep infiltration thickness. Thus, high LMP1 expression may contribute to the tissue invasion of ENKTL-NT. CONCLUSIONS Any patient with nasal ala soft-tissue invasion, nasal floor thickness >2.0 mm/nasal septum thickness >2.5 mm on CT imaging or high LMP1 expression should prompt immediate histopathologic diagnosis to rule out ENKTL-NT in clinical practice.

EBV-Positive Lymphoproliferations of B- T- and NK-Cell Derivation in Non-Immunocompromised Hosts

The contribution of Epstein-Barr virus (EBV) to the development of specific types of benign lymphoproliferations and malignant lymphomas has been extensively studied since the discovery of the virus over the last 50 years. The importance and better understanding of the EBV-associated lymphoproliferative disorders (LPD) of B, T or natural killer (NK) cell type has resulted in the recognition of new entities like EBV+ mucocutaneous ulcer or the addition of chronic active EBV (CAEBV) infection in the revised 2016 World Health Organization (WHO) lymphoma classification. In this article, we review the definitions, morphology, pathogenesis, and evolving concepts of the various EBV-associated disorders including EBV+ diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS), EBV+ mucocutaneous ulcer, DLBCL associated with chronic inflammation, fibrin-associated DLBCL, lymphomatoid granulomatosis, the EBV+ T and NK-cell LPD of childhood, aggressive NK leukaemia, extranodal NK/T-cell lymphoma, nasal type, and the new provisional entity of primary EBV+ nodal T- or NK-cell lymphoma. The current knowledge regarding the pathogenesis of B-cell lymphomas that can be EBV-associated including Burkitt lymphoma, plasmablastic lymphoma and classic Hodgkin lymphoma will be also explored.

Primary cutaneous NK/T-cell lymphoma of nasal type: an age-related lymphoproliferative disease?

Among extranodal NK/T-cell lymphoma of nasal type (NKTL), the extranasal variant (ENKTL) is known to have a worse prognosis with advanced clinical stage than the nasal variant of NKTL. However, detailed clinicopathological features of the localized extranasal disease have not been well documented in English literature. Here, we described the clinicopathological profiles of 14 patients with stage I ENKTL, including 7 in the skin, 5 in the gastrointestinal tract, and 2 in the central nervous system, highlighting the distinctiveness of the first. The 7 primary cutaneous (PCNKTL) cases were characterized by an older onset age (median, 76 versus 53 years, P=.012) and a more favorable clinical course (P=.041) compared with 17 patients with stages II-IV ENKTL that showed cutaneous involvement. The skin lesions in the PCNKTL group were distributed in the face or neck (n=4) and limbs (n=3) but not the trunk, which was most frequently affected (60%, P=.017) in the latter group. Furthermore, the stage I cutaneous disease showed a female predominance (male-female, 2:5 versus 7:0; P=.021) and a significantly more favorable survival compared with the noncutaneous stage I ENKTL (P=.037). These results suggest that PCNKTL constitute a distinct subgroup in the nasal-type lymphoma spectrum.

Virus-associated neoplasms of the nasopharynx and sinonasal tract: diagnostic problems

A significant fraction of nasopharyngeal and sinonasal tumors are associated with Epstein-Barr virus (EBV) or human papillomavirus (HPV). Nasopharyngeal carcinoma (NPC) and extranodal NK/T-cell lymphoma harbor EBV in practically all cases, although a small proportion of cases of the former harbor HPV. Sinonasal inverted papillomas harbor HPV in about 25% of cases. Sinonasal squamous cell carcinomas harbor transcriptionally active HPV in about 20% of cases, and limited data suggest that this subset has a better prognosis than the HPV-negative subset. This review addresses the diagnostic issues of the EBV-associated tumors. Difficulties in diagnosis of NPC may be encountered when there are prominent crush artifacts, many admixed lymphoid cells masking the neoplastic cells, or numerous interspersed granulomas, whereas benign cellular components (epithelial crypts and germinal centers) and reactive lymphoid hyperplasia can potentially be mistaken for NPC. Immunostaining for pan-cytokeratin and/or in situ hybridization for EBER can help in confirming or refuting a diagnosis of NPC. The main diagnostic problem of extranodal NK/T-cell lymphoma is recognition of the neoplastic nature of those examples predominated by small cells or showing a mixture of cells. The identification of a destructive infiltrate (dense expansile infiltrate; angiocentric growth) and definite cytologic atypia (clear cells; many medium-sized cells) would favor a diagnosis of lymphoma, which can be supported by immunohistochemistry (most commonly CD3+, CD5-, CD56+) and in situ hybridization for EBER. In conclusion, among nasopharyngeal and sinonasal neoplasms, demonstration of EBV may aid in diagnosis, particularly NPC and extranodal NK/T-cell lymphoma. Demonstration of HPV does not have a role yet in diagnosis, although this may change in the future.

Predictors of survival of natural killer/T-cell lymphoma, nasal type, in a non-Asian population: a single cancer centre experience

Background

Natural killer/T-cell lymphoma (NKTCL), part of T-cell and NK-cell neoplasms in the World Health Organisation (WHO) classification, is an aggressive lymphoma with poor prognosis more predominantly seen in Asian and South American countries. This study evaluates the factors associated with survival among patients with newly diagnosed NKTCL in Peru.

Methods

Information was abstracted from medical records (MR) for all NKTCL patients >13 years of age at the Instituto Nacional de Enfermedades Neoplasicas (INEN) between 2002 and 2011. The estimate of the survival curves was performed by the Kaplan-Meier method, and the difference was computed by the log-rank test.

Results

Around 226 MR were reviewed, 153 met the selection criteria, the median age was 40 years (14–84). The median progression-free survival (PFS) was 20 months, five year PFS was 42.6%, univariable analysis (UA) showed statistical significance (p < 0.05) for male sex, non-nasal primary site, advanced clinical stages, B symptoms, poor performance status, regional nodal involvement (RNI). In the multivariate analysis the only poor prognostic factors was primary non-nasal (Hazard ratio (HR) = 2.40, 95% confidence interval (CI) = 1.43– 4.02, P = 0.01). The median overall survival (OS) was 49 months, five year OS was 48.9%, UA showed statistical significance for non-nasal primary site, advanced clinical stages, B symptoms, lactate dehydrogenase (LDH) > normal, RNI and local tumour invasion. In the multivariate analysis, primary non-nasal was the only poor prognostic factor with HR = 2.57, 95% CI = 1.37–4.83, P = 0.03.

Conclusions

In Peru, OS of NKTCL is similar to other countries. This result suggests that non-nasal NKTCL is the only poor prognostic factor of OS and PFS.

Racial Patterns of Peripheral T-Cell Lymphoma Incidence and Survival in the United States

PURPOSE

To compare incidence and survival of peripheral T-cell lymphoma (PTCL) subtypes among US racial/ethnic groups.

METHODS

Patients with PTCL (age ≥ 15 years; 2000 to 2012) were identified in the Surveillance, Epidemiology, and End Results (SEER) registries. Race/ethnicity was categorized as non-Hispanic white, black, Asian/Pacific Islander, Hispanic white, or American Indian/Alaskan native. Age-standardized annual incidence rates and incidence rate ratios were estimated with 95% CIs, and case-case odds ratios were estimated by race/ethnicity using polytomous regression. Survival was estimated from SEER follow-up data with Cox regression.

RESULTS

Thirteen thousand one hundred seven patients with PTCL were identified. Annual PTCL incidence was highest in blacks and lowest in Native Americans. Compared with non-Hispanic whites, blacks had a higher incidence of PTCL not otherwise specified (PTCL-NOS), anaplastic large-cell lymphoma, and adult T-cell leukemia/lymphoma (ATLL) and a lower incidence of angioimmunoblastic T-cell lymphoma (AITL); Asians/Pacific Islanders had a higher incidence of AITL, extranodal nasal-type natural killer/T-cell lymphoma and NK-cell leukemia (ENKCL), and ATLL and a lower incidence of anaplastic large-cell lymphoma; Hispanics had a higher incidence of AITL and ENKCL; and Native Americans had a lower incidence of PTCL-NOS (all P < .05). The ratio of ENKCL to PCTL-NOS among Native Americans, Asians/Pacific Islanders, and Hispanic whites was approximately three- to four-fold the same ratio among non-Hispanic whites. Survival varied significantly by race/ethnicity (P < .001), with blacks in particular experiencing shorter survival for most subtypes.

CONCLUSION

Striking variation in incidence, proportions of PTCL subtypes, and survival was observed. Aspects of these PTCL subtype patterns, such as for ENKCL and ATLL, were similar to corresponding global populations. Despite the small population size and limited number of Native American patients, PTCL subtype frequencies in this group were distinct but most similar to Hispanic whites. Survival disparities were evident, especially for blacks compared with non-Hispanic whites.

Cutaneous lymphoma in Japan: a nationwide study of 1733 patients

Types of cutaneous lymphoma (CL) and their incidences may vary among geographic areas or ethnic groups. The present study aimed to investigate the incidences of various CL in Japan, using epidemiological data from a nationwide registration system for CL. Between 2007 and 2011, 1733 new patients with CL were registered from over 600 dermatological institutes in Japan. The 1733 patients registered included 1485 (85.7%) patients with mature T- and natural killer (NK)-cell neoplasms, 224 (12.9%) with B-cell neoplasms and 24 (1.4%) with blastic plasmacytoid dendritic cell neoplasm. Mycosis fungoides (MF) is the most common CL subtype in the present study (750 patients, 43.3%). The proportion of MF patients with early-stage disease was 73%, similar to that of previous studies from other cohorts. The incidence rates of adult T-cell leukemia/lymphoma and extranodal NK/T-cell lymphoma, nasal type were 16.7% and 2.0%, respectively, which may account for the higher incidence of mature T- and NK-cell neoplasms in Japan, as compared with that in the USA and Europe. A male predominance was observed in most types of CL, except for several CL subtypes such as subcutaneous panniculitis-like T-cell lymphoma.

Extranodal natural killer/T-cell lymphoma, nasal type in Taiwan: a relatively higher frequency of T-cell lineage and poor survival for extranasal tumors

Extranodal natural killer (NK)/T-cell lymphoma, nasal type, is a predominantly extranodal lymphoma associated with Epstein-Barr virus occurring most frequently in the upper aerodigestive tract. There are limited reports on cellular origin and prognostic factors. We retrospectively investigated 73 cases with a median age of 54 years and a male-female ratio of 2.0:1. The upper aerodigestive tract (nasal group) was the most common site of involvement (51 cases; 70%). The other organs (n = 22; extranasal group) included the skin (12 cases; 16%) and gastrointestinal tract (5; 7%). Of the 70 cases with complete staging, 71% had stage I/II disease. All cases were positive for Epstein-Barr virus by in situ hybridization. Using immunohistochemistry and clonality assay for T-cell receptor gene rearrangement, these tumors were classified into NK (n = 39; 53%), T (n = 13; 18%), and indeterminate lineage (n = 21; 29%). The only clinicopathological difference among these 3 groups was rare CD5 expression in the NK-cell group. Nasal tumors were more frequently of NK-cell origin, and extranasal tumors were equally of either T- or NK-cell origin. The 5-year overall survival rate was 35.6%. The overall survival time was shorter in the extranasal group, although there was no statistical difference in age, sex, and histologic or immunophenotypic features between the 2 groups. Excluding the cases with indeterminate lineage, 75% of cases were of NK lineage; and 25%, T lineage. Extranasal tumors were more aggressive than their nasal counterparts. A prospective national study is warranted for a better understanding of the clinicopathological and genetic features of this uncommon tumor and the prognostic factors.

Extranodal natural killer/T-cell lymphoma, nasal type, involving the skin, misdiagnosed as nasosinusitis and a fungal infection: A case report and literature review

The present study reports a case of extranodal natural killer (NK)/T-cell lymphoma, nasal type, involving the skin. The clinical manifestations, pathological characteristics, treatment and prognosis of the case were analyzed to improve the clinical diagnosis and treatment for this disease. The patient was a 56-year-old male, presenting with dark red nodules and plaques that had been visible on the nose for half a year. Based on the skin lesions and histopathological and immunohistochemical examination results, the patient was diagnosed with extranodal NK/T-cell lymphoma, nasal type. This disease has unique histopathological and immunohistochemical features and a high malignancy. The condition tends to be misdiagnosed and has a poor prognosis, but seldom involves the skin. In the present case, only radiotherapy was performed, with no relapse occurring within 6 months.

An A91V SNP in the perforin gene is frequently found in NK/T-cell lymphomas

NK/T-cell lymphoma (NKTCL) is the most frequent EBV-related NK/T-cell disease. Its clinical manifestations overlap with those of familial haemophagocytic lymphohistiocytosis (FHLH). Since PERFORIN (PRF1) mutations are present in FHLH, we analysed its role in a series of 12 nasal and 12 extranasal-NKTCLs. 12.5% of the tumours and 25% of the nasal-origin cases had the well-known g.272C>T(p.Ala91Val) pathogenic SNP, which confers a poor prognosis. Two of these cases had a double-CD4/CD8-positive immunophenotype, although no correlation was found with perforin protein expression. p53 was overexpressed in 20% of the tumoral samples, 80% of which were of extranasal origin, while none showed PRF1 SNVs. These results suggest that nasal and extranasal NKTCLs have different biological backgrounds, although this requires validation.

Comparison between presence of epstein barr virus in nodal and extra nodal diffuse large B cell lymphoma of head and neck, an Iranian experience

Background

Epstein Barr Virus (EBV) is one of the most common viral infections in human population. EBV has a significant role in pathogenesis of Hodgkin's lymphoma, Burkitt's lymphoma and nasopharyngeal carcinoma. The role of EBV in non-Hodgkin’s lymphoma, diffuse large B cell (NHL - DLBL) in the head and neck is controversial.

Objectives

The purpose of this study is to find out the difference between the presence of Epstein Barr virus in nodal and extra nodal lymphoma of head and neck.

Patients and Methods

A total of 30 cases of DLBL in two separate groups were collected from pathology department. The first group was consisted of 15 patients with DLBL of neck lymph node and the other was consisted of 15 patients with extra nodal DLBL of head and neck mainly in palatine tonsil. Both immune-histo-chemical (IHC) study and polymerase chain reaction (PCR) for detection of late membrane antigen (LMP) were performed on formalin fixed paraffin embedded tissue.

Results

All 30 cases were negative for EBV in IHC method. But in PCR method, 10% of patients were positive for LMP gene. There were 2 positive cases in nodal lymphoma and 1 positive case in extra nodal lymphoma group.

Conclusions

Compare with PCR method, it seems that IHC is not a sensitive method for detection of EBV. Overall, the finding of EBV in NHL depends on site, type of lymphoma and the detection method.

Complete remission after first-line radio-chemotherapy as predictor of survival in extranodal NK/T cell lymphoma

Background

Extranodal nasal-type NK/T-cell lymphoma is a rare and severe disease. Considering the rarity of this lymphoma in Europe, we conducted a multicentric retrospective study on nasal-type NK/T cell lymphoma to determine the optimal induction strategy and identify prognostic factors.

Methods

Thirty-six adult patients with nasal-type NK/T-cell lymphoma were recruited and assessed. In total, 80 % of patients were classified as having upper aerodigestive tract NK/T-cell lymphoma (UNKTL) and 20 % extra-upper aerodigestive tract NK/T-cell lymphoma (EUNKTL).

Results

For advanced-stage disease, chemotherapy alone (CT) was the primary treatment (84 % vs. 10 % for combined CT + radiation therapy (RT), respectively), while for early-stage disease, 50 % of patients received the combination of CT + RT and 50 % CT alone. Five-year overall survival (OS) and progression-free survival (PFS) rates were 39 % and 33 %. Complete remission (CR) rates were significantly higher when using CT + RT (90 %) versus CT alone (33 %) (p < 0.0001). For early-stage disease, CR rates were 37 % for CT alone versus 100 % for CT + RT. Quality of response was significantly associated with survival, with 5-year OS being 80 % for CR patients versus 0 % for progressive disease patients (p < 0.01).

Conclusion

Early RT concomitantly or sequentially with CT led to improved patient outcomes, with quality of initial response being the most important prognosticator for 5-year OS.

Extranodal NK/T-cell lymphoma, nasal type, includes cases of natural killer cell and αβ, γδ, and αβ/γδ T-cell origin: a comprehensive clinicopathologic and phenotypic study

Extranodal NK/T-cell lymphoma (ENKTL), nasal type, may be of NK or T-cell origin; however, the proportion of T-ENKTLs and whether they are of αβ or γδ type remains uncertain. To elucidate the cell of origin and detailed phenotype of ENKTL and assess any clinicopathologic associations, 67 cases of ENKTL from Thailand were investigated, together with 5 γδ enteropathy-associated T-cell lymphomas (EATLs) for comparison. In all, 70% of the ENKTL were T-cell receptor (TCR) β,γ and, in cases tested, δ negative (presumptive NK origin); 5% were TCR γδ, 3% were TCR αβ, 1% were TCR αβ/γδ, and 21% were indeterminate. Out of 17 presumptive NK-ENKTLs tested, 3 had clonal TCR rearrangements. All cases were EBV and TIA-1; >85% were positive for CD3, CD2, granzyme B, pSTAT3, and Lsk/MATK; and all were CD16. Presumptive NK-ENKTLs had significantly more frequent CD56 (83% vs. 33%) and CXCL13 (59% vs. 0%) but less frequent PD-1 (0% vs. 40%) compared with T-ENKTLs. Of the NK-ENKTLs, 38% were Oct-2 compared with 0% of T-ENKTLs, and 54% were IRF4/MUM1 compared with 20% of T-ENKTLs. Only αβ T-ENKTLs were CD5. Intestinal ENKTLs were EBV and had significantly more frequent CD30, pSTAT3, and IRF4/MUM1 expression but less frequent CD16 compared with γδ EATL. Significant adverse prognostic indicators included a primary non-upper aerodigestive tract site, high stage, bone marrow involvement, International Prognostic Index ≥2, lack of radiotherapy, Ki67 >40%, and CD25 expression. The upper aerodigestive tract ENKTLs of T-cell origin compared with those of presumptive NK origin showed a trend for better survival. Thus, at least 11% of evaluable ENKTLs are of T-cell origin. Although T-ENKTLs have phenotypic and some possible clinical differences, they share many similarities with ENKTLs that lack TCR expression and are distinct from intestinal γδ EATL.

Racial patterns of extranodal natural killer/T-cell lymphoma, nasal type, in California: a population-based study

In order to investigate whether the clinical behaviour of extranodal natural killer/T-cell lymphoma, nasal type (ENKTL) varies by race within a geographic region, we identified a total of 213 non-Hispanic whites, Hispanics and Asians/Pacific islanders (APIs) diagnosed with ENKTL in the California Cancer Registry between 2001 and 2008. The incidence and outcomes of the disease in these racial groups were analysed. The incidence rates in non-Hispanic whites, Hispanics and APIs were 0.05, 0.18 and 0.23 per 100,000 person-years, respectively, among males; and 0.03, 0.07 and 0.10 per 100,000 person-years, respectively, among females. The overall survival (OS) at 5 years was 28.6% in non-Hispanic whites, 30.4% in Hispanic, and 24.0% in APIs. In multivariate analysis, distant versus local/regional disease (Hazard Ratio [HR]=2.01, 95% confidence interval [CI]: 1.36, 2.96), initial treatment with chemotherapy plus radiotherapy (HR=0.39, 95% CI: 0.22, 0.70) or radiotherapy alone (HR=0.48, 95% CI: 0.23, 0.99) versus no therapy were associated with OS. However, OS was not affected by age, sex, race, chemotherapy alone, socioeconomic status, or human immunodeficiency virus infection. In conclusion, ENKTL is more common and clinically more similar among Hispanics and APIs than non-Hispanic whites with poor outcome in all racial groups.

Pathobiology of Epstein-Barr virus-driven peripheral T-cell lymphomas

In the present review, the authors described the pathobiological features of Epstein-Barr virus (EBV)-driven T/natural killer cell-derived malignancies. These rare tumors appear to be quite heterogeneous with regard to both clinical and pathologic features. Nonetheless, some elements, especially regarding the possible role of EBV (ie, genomic predisposition, pathogenesis, pattern of latency), are similar, enforcing the concept of a causative role for the virus. In clinical practice, although definitely rare in Western countries, the tumors are not exceptional; thus, they should be taken into account in the differential diagnosis of T-lymphoproliferative disorders, also considering the need for extremely prompt intervention. The prognosis of such tumors is generally poor using current approaches. A better understanding of their molecular pathogenesis may lead to significant therapeutic improvements. For example, the nuclear factor-KB pathway and platelet-derived growth factor receptor inhibition may represent 2 options to be tested in clinical trials.

Deciphering the role of Epstein-Barr virus in the pathogenesis of T and NK cell lymphoproliferations

Epstein-Barr virus (EBV) is a highly successful herpesvirus, colonizing more than 90% of the adult human population worldwide, although it is also associated with various malignant diseases. Primary infection is usually clinically silent, and subsequent establishment of latency in the memory B lymphocyte compartment allows persistence of the virus in the infected host for life. EBV is so markedly B-lymphotropic when exposed to human lymphocytes in vitro that the association of EBV with rare but distinct types of T and NK cell lymphoproliferations was quite unexpected. Whilst relatively rare, these EBV-associated T and NK lymphoproliferations can be therapeutically challenging and prognosis for the majority of patients is dismal. In this review, we summarize the current knowledge on the role of EBV in the pathogenesis of these tumours, and the implications for treatment.

Prognostic markers in peripheral T-cell lymphoma

Based on their own experience and knowledge of the literature, the authors review the pathobiological characteristics of peripheral T-cell lymphomas (PTCLs), focusing on the available prognostic indicators. The International Prognostic Index (IPI), which is based on age, performance status, lactate dehydrogenase [LDH], stage, and extranodal involvement, appears to be efficient as a prognostic index for PTCLs, at least in part and especially for certain PTCL subtypes. However, it is not so satisfactory for the two commonest PTCLs, PTCL not otherwise specified (PTCL/NOS) and angioimmunoblastic T-cell lymphoma (AITL), for which novel scores, possibly based on the biologic features of the tumors, have been explored. An Italian cooperative group proposed a revision of the IPI for PTCL unspecified (PTCL-U), the Prognostic Index for PTCL-U (PIT), which includes age, performance status, LDH, and bone marrow involvement. The PIT apparently offered some advantages, but they were not confirmed in subsequent studies. A clinical-biological score (the Bologna score) was then proposed, including tumor proliferation and clinical features (age, LDH, and performance status). This score appears promising and offers the intriguing advantage of integrating biological and clinical elements, but independent validation on a large series is still warranted. More recently, gene expression profiling has been used to identify novel molecular prognostic factors. In particular, inactivation of the NFκB pathway, high expression of proliferation-associated genes, and cytotoxic molecular phenotype seem to be associated with a worse outcome. So far, however, none of these indicators has been validated in an independent series. Finally, various reports have dealt specifically with the prognostication of NK-derived tumors, including nasal and nasal-type lymphomas. Both the IPI and dedicated models have turned out to be of prognostic relevance for these tumors. In conclusion, although the IPI is somewhat effective for PTCL prognostication, novel scores that are more refined and possibly disease-specific are warranted. The validation process for several models, including clinical-pathological and molecular models, is now ongoing.

Prevalence of Epstein-Barr virus associated with nasal lymphoma in patients attending the regional hospital of Valdivia, Chile, between 1987 and 2005

Epstein-Barr virus (EBV) is a ubiquitous herpes virus with a widespread infection in the world's adult population. EBV has been associated with human malignancies, mainly the nasal type NK/T cell lymphoma. The disease is more frequent in Asian than in Western countries. However, there are few studies from Latin American countries. The aim of this study was to determine the prevalence of EBV in patients with nasal lymphomas diagnosed in the Regional Hospital of Valdivia, southern Chile, during 1987-2005. Immunohistochemistry was done on paraffin sections using anti-CD3epsilon, anti-CD20, and anti-CD56. The presence of small ribonucleic acids (RNAs) of EBV was detected in paraffin sections by in situ hybridization using oligonucleotides targeting EBV-encoded small RNAs. The present study revealed a prevalence of 27.7% of Hodgkin's lymphomas and 72.3% of non-Hodgkin's lymphomas. From the latter group, there was a prevalence of 2.9% (10 cases) of nasal lymphoma. From these 10 cases, 6 (60%) were NK/T cell lymphomas, nasal type; 1 case (10%) was a T-cell phenotype; and 3 cases (30%) were B-cell phenotype. The prevalence was higher than reports from Western countries, but lower than the reports from Asian countries. These results agreed with previous reports suggesting that EBV is strongly associated with T lymphomas. This study contributes new epidemiological data on EBV in Chile.

Treatment outcome of radiotherapy alone versus radiochemotherapy in early stage nasal natural killer/T-cell lymphoma

This study aims to investigate the prognostic factors and long-term treatment outcome in patients with early stage nasal natural killer (NK)/T-cell lymphoma. Sixty-four patients were recruited in this study, whose clinical and laboratory data were collected from hospital records. Early stage (stage IE: 51, stage IIE: 13) nasal NK/T-cell lymphoma (NNTCL) was established according to Ann Arbor staging classification. Among these patients, 23 received radiotherapy (RT) alone, the remaining 41 cases were treated with radiochemotherapy (RCT) comprised of 1-6 cycles of anthracycline-based chemotherapeutic regimens. Results show that the median overall survival (OS) time was 41 months. The 5-year OS and progression-free survival rates were 59.2 and 52.3%, respectively. The 5-year OS rate for patients who received RT alone was 57.9%, whereas that for patients who received RCT was 61.5% (P = 0.47). There is no significant difference between two treatment modalities. Multivariate analysis showed that Eastern Cooperative Oncology Group performance status (PS) score > or = 2, local tumor invasion out of nasal cavity, and lower complete remission (CR) rates in the initial treatment were significant unfavorable independent prognostic factors. Taken together, our study suggests that RCT did not improve the survival rate of patients with early stage NNTCL. PS score before treatment, local tumor invasion out of nasal cavity, and CR rate of the primary treatment may be independent prognostic factors among the subtype lymphoma entity.

Undifferentiated malignant neoplasms of the sinonasal tract

CONTEXT

The most commonly encountered malignant neoplasms of the sinonasal tract are the keratinizing and nonkeratinizing types of squamous cell carcinoma. However, this complex anatomic region may represent the site of aggressive, non-squamous cell epithelial and nonepithelial malignant neoplasms of varying histogenesis, which are grouped under the term undifferentiated malignant neoplasms. Frequently, these undifferentiated malignancies share clinical and light microscopic features, which makes differentiation of one from the other virtually impossible without the use of adjunct analyses (eg, immunohistochemistry, electron microscopy, or molecular biologic studies). These tumors often are clinically aggressive and usually fatal, despite all attempts at controlling disease. Nevertheless, differentiating these tumors has clinical import because advances in therapeutic intervention may increase survival with good quality of life, and in some instances may achieve a cure.

OBJECTIVE

To compare and contrast the clinical, light microscopic, and immunohistochemical features of sinonasal undifferentiated malignant neoplasms.

DATA SOURCES

Case-derived material and literature review.

CONCLUSIONS

A variety of undifferentiated malignant neoplasms occur in the sinonasal tract with overlapping clinical and pathologic findings. In limited biopsy material, differentiation of these tumor types can be challenging. The pathologist plays a primary role in establishing the correct diagnosis, which often necessitates the use of adjunct studies that allow for differentiating among these neoplasms.

Expression of the multidrug resistance protein MRP and the lung-resistance protein LRP in nasal NK/T cell lymphoma: further exploring the role of P53 and WT1 gene

AIMS

Nasal NK/T-cell lymphoma (NKTL) is relatively common in the adult men of Asia. Many patients with nasal NKTL have poor response to therapy. Some of them show P-glycoprotein over-expression. To investigate the expression of other multidrug resistance proteins (MDR) and possible regulatory factors in nasal NKTL, the clinical and pathological features are described.

METHODS

Thirty Chinese adults with nasal NKTL are presented. Immunohistochemical study was carried out to detect multidrug resistance-associated protein 1 (MRP) and lung resistance-related protein (LRP). The association between possible regulatory proteins (P53 and WT1) and MDR were explored. In situ hybridisation for Epstein-Barr virus (EBV) detection, polymerase chain reaction assay for T-cell receptor gene and direct sequencing for the P53 gene were performed.

RESULTS

Seven (23.3%) and eight (26.7%) patients showed immunoreactivity of MRP and LRP, respectively. Positive staining for both markers was identified in 6.7% (2 cases). The EBV was detected in most cases (97%). Twenty-six (86.7%) cases expressed positive nuclear staining of P53. However, of the cases analysed for P53 mutation, none showed a mutaion at the hot spots studied. WT1 protein was not detected in the nasal NKTL.

CONCLUSION

Our study reports expression of MRP and LRP in nasal NKTL. The over-expression of P53 is probably associated with high incidence of EBV infection and unlikely a regulatory protein for the expression of MRP and LRP. Further studies are necessary to validate the association between P53 mutation and expression of MRP and LRP in nasal NKTL.

Low frequency of Epstein Barr virus association and high frequency of p53 overexpression in an Argentinean pediatric T-cell lymphoma series

T-cell non-Hodgkin's lymphomas (NHLs) represent 10% to 15% of all diagnosed lymphomas in Western countries. Various geographic frequencies of T-cell NHL have been documented, in part reflecting increased exposure to pathogenic factors such as Epstein-Barr virus (EBV). Our aims were to assess EBV and p53 expression in Argentine pediatric T-cell lymphoma and to correlate them with patients' survival. Epstein-Barr encoded RNAs (EBERs) in situ hybridization and LMP1 and p53 immunohistochemical staining were performed on formalin-fixed paraffin-embedded lymph node biopsies from 25 pediatric T-lymphoma patients. In 17 of 25 samples good-quality DNA was obtained, and EBER polymerase chain reaction was assessed to confirm in situ hybridization and immunohistochemical results. Epstein-Barr virus expression was found in 8.0% of cases. p53-positive staining was distributed in 92% of pediatric cases. Kaplan-Meier survival analysis showed that neither EBV nor p53 expression was statistically significantly associated with event-free survival. Our data showed a low frequency of EBV association with pediatric T-cell lymphoma. It seems that p53 plays an important role in proliferation in our studied population, since it is overexpressed in 92% of T-cell lymphoma cases.

Nasal-type NK/T-cell lymphoma presenting as hemophagocytic syndrome in an 11-year-old Mexican boy

Recently established by the World Health Organization classification, "nasal" and "nasal-type" NK/T-cell lymphoma arise from natural killer (NK) cells. They have distinct clinicopathologic features, specific genotype and phenotype, and a high association with Epstein-Barr virus infection. Nasal-type NK/T-cell lymphoma arise from extranasal sites including skin, soft tissue, gastrointestinal tract, liver, spleen, testes, lung, and central nervous system. Most cases are reported from Asia and South America in adults. There are very few cases reported in the pediatric age group. We report an 11-year-old child with extranodal nasal-type NK/T-cell lymphoma presenting as hemophagocytic syndrome and multiorgan system failure with fatal outcome.

Clinical differences between nasal and extranasal natural killer/T-cell lymphoma: a study of 136 cases from the International Peripheral T-Cell Lymphoma Project

Among 1153 new adult cases of peripheral/T-cell lymphoma from 1990-2002 at 22 centers in 13 countries, 136 cases (11.8%) of extranodal natural killer (NK)/T-cell lymphoma were identified (nasal 68%, extranasal 26%, aggressive/unclassifiable 6%). The disease frequency was higher in Asian than in Western countries and in Continental Asia than in Japan. There were no differences in age, sex, ethnicity, or immunophenotypic profile between the nasal and extranasal cases, but the latter had more adverse clinical features. The median overall survival (OS) was better in nasal compared with the extranasal cases in early- (2.96 vs 0.36 years, P < .001) and late-stage disease (0.8 vs 0.28 years, P = .031). The addition of radiotherapy for early-stage nasal cases yielded survival benefit (P = .045). Among nasal cases, both the International Prognostic Index (P = .006) and Korean NK/T-cell Prognostic Index (P < .001) were prognostic. In addition, Ki67 proliferation greater than 50%, transformed tumor cells greater than 40%, elevated C-reactive protein level (CRP), anemia (< 11 g/dL) and thrombocytopenia (< 150 x 10(9)/L) predicts poorer OS for nasal disease. No histologic or clinical feature was predictive in extranasal disease. We conclude that the clinical features and treatment response of extranasal NK/T-cell lymphoma are different from of those of nasal lymphoma. However, the underlying features responsible for these differences remain to be defined.

Expression levels of apoptosis-related proteins and Ki-67 in nasal NK / T-cell lymphoma

OBJECTIVES

Nasal natural killer (NK)/T-cell lymphoma is characterized by chemo-resistance, angiodestruction, and aggressive tumor progression. Few studies exist on molecular characteristics of this disease entity.

METHODS

Expression levels of major apoptosis-related proteins Bcl-2, Bcl-x, Mcl-1, Bax, and a proliferative marker Ki-67 were analyzed in 11 nasal NK/T-cell lymphoma cases by immunohistochemical methods. Nine cases were of NK-cell lineage and two cases were of T-cell lineage. For comparison, 12 follicular lymphoma (FL) cases and 16 diffuse large B-cell lymphoma (DLBCL) cases were also studied.

RESULTS AND CONCLUSIONS

Bax expression was low in all nasal NK-cell lymphoma cases, which constitute the major population of nasal NK/T-cell lymphoma. Bax expression in nasal NK-cell lymphoma was similar to FL and significantly lower compared with DLBCL. Bcl-2 expression was significantly lower in nasal NK/T-cell lymphoma compared with that of FL and DLBCL. Bcl-x expression was high in all three lymphomas. Two distinct Mcl-1 expression groups existed for nasal NK/T-cell lymphoma (6.2 +/- 5.2% and 59.1 +/- 12.3%, 95% CI). Ki-67 expression was high in nasal NK/T-cell lymphoma, and worse prognostic groups tended to express higher levels of Ki-67. The results suggest a combination of impaired apoptosis and aggressive proliferation in nasal NK/T-cell lymphoma, and may provide explanations for its poor prognosis.

The primary role of the otolaryngologist in managing pediatric sinonasal malignancies: an extranodal NK/T-cell lymphoma originating from the inferior turbinate mucosa of the nasal cavity

The primary role of the otolaryngologist in managing patients with a sinonasal malignancy is to make an early diagnosis. However, this can be difficult because of the relatively nonspecific signs and symptoms associated with the progress of the disease, especially in the pediatric population. Recently, we observed a nasal extranodal natural killer/T-cell lymphoma in a 12-year-old girl with a 6-month history of right nasal obstruction. Her symptom worsened gradually despite medical treatment at a private hospital. Endoscopic examination revealed ulcerative changes and hypertrophy of the right inferior turbinate mucosa. The histopathology and immunohistochemical staining of a punch biopsy confirmed the diagnosis. In this case, we emphasize the importance of a complete endoscopic examination of the nasal cavity in a pediatric patient with unilateral nasal symptoms and the possible necessity of referral to an otolaryngologist to prevent misdiagnosis and management of the pathology as benign.

The spectrum of Epstein-Barr virus-associated lymphoproliferative disease in Korea: incidence of disease entities by age groups

This study is to identify the spectrum of Epstein-Barr virus (EBV)-positive lymphoproliferative diseases (LPD) and relationships between these diseases in Korea. The EBV status and clinicopathology of 764 patients, including acute EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH), chronic active EBV (CAEBV) infections, B-LPD arising in chronic latent EBV infection, T & natural killer (NK) cell non-Hodgkin's lymphomas (NHL), B-NHLs, and Hodgkin's lymphomas (HD), were analyzed. T or NK cell NHLs were the most common forms of EBV-positive NHLs (107/167, 64%); among these, nasal-type NK/T cell lymphomas were the most common (89/107, 83%). According to the age, Burkitt's lymphoma was the most common in early childhood; in teenagers, chronic (active) EBV infection-associated LPD was the most common type. The incidence of NK/T cell lymphoma began to increase from the twenties and formed the major type of EBV-associated tumor throughout life. Diffuse large B cell lymphoma formed the major type in the sixties and seventies. In conclusion, primary infections in early childhood are complicated by the development of CAEBV infections that are main predisposing factors for EBV-associated T or NK cell malignancies in young adults. In old patients, decreased immunity associated with old age and environmental cofactors may provoke the development of peripheral T cell lymphoma, unspecified, and diffuse large B cell lymphoma.

Nasal NK/T-cell lymphoma: epidemiology and pathogenesis

Nasal NK/T-cell lymphoma (NKTCL) is an uncommon disease, but usually shows a highly aggressive clinical course. The disease is much more frequent in Asian and Latin American countries than in Western countries, and is universally associated with Epstein–Barr virus (EBV) infection. Analyses of gene mutations, especially p53 and c-KIT, revealed the different frequencies by district. Epidemiological studies revealed the changes of the disease frequency in Korea during the period from 1977–1989 to 1990–1996. Case-control study showed that the exposure to pesticides and chemical solvents could be causative of NKTCL. Further studies including HLA antigen typing of patients is necessary to further clarify the disease mechanism.

A unique case of adolescent CD56-negative extranodal NK/T-cell lymphoma, nasal type

Mature T-cell neoplasms are unusual in the pediatric population. The majority of these neoplasms in the United States are anaplastic large cell lymphomas (ALCL) characterized by CD30 and anaplastic lymphoma kinase-1 expression. Extranodal natural killer/T (NK/T)-cell lymphomas, nasal type, are extremely rare. Extranodal NK/T-cell lymphomas often express CD56, are associated with Epstein-Barr virus, and are negative for CD30. Clinically, extranodal NK/T-cell lymphomas are much more aggressive than ALCL, and require different treatment strategies. The authors present an adolescent male with a CD56 negative extranodal NK/T-cell lymphoma, nasal type. The lymphoma was partially positive for CD30, diffusely positive for EBV by in situ hybridization, and clonal for T-cell receptor gene rearrangement and cytogenetic abnormalities. The patient was aggressively treated with chemotherapy, surgery, and radiation. More than 2 years from completion of the therapy, the patient remains disease free. This case highlights the importance and difficulty of accurate identification of this type of rare tumor. We further present the literature review and discuss the diagnostic criteria for extranodal NK/T lymphoma using morphologic, immunologic, molecular, and cytogenetic information.